Places to Shop - Nonno 21

Nonno 21 is located near Nambu bus terminal a major transport hub in Seoul.

Their online store is www.nonno21.com

Like Hobby Plus I strongly suspect Nonno21 might be retail only. Certainly their website doesn't display magic very prominently. 

Contact Details
Phone number: 02-3465-0094
Korean Street address: 서울특별시 서초구 서초동 국제전자센터 9층

Places to Shop - Hobby Plus

Located very close to Nambu bus terminal Hobby Plus is registered with Wizards for tournament play but don't really have the space for it. 
I am under the impression they just sell sealed product.

Their online store is http//www.hobby-plus.co.kr

Contact Details
Phone number: 070-8614-4900
Email address: info@hobby-plus.co.kr
Korean street address: 서울특별시 서초구 서초동 국제전자센터 9층

Places to Play - PlayFirst, Goyang

Like DiveDice, Playfirst has an online presence and also doesn't have a space in its name.

It's also a little out in the sticks unless you are a resident of North Western Gyeonggi do.

They have both a Korean http//www.PlayFirst.co.kr and English http://www.playfirststore.com/ web store which is very impressive.

Contact Details
Phone number: 031-966-9985
Korean Street address: 경기도 고양시 일산동구 식사동 809-13번지 2층

Edit (23/12/2013): Their English site is under renovation and looks to have changed web address to http://www.draw2cards.com/

Places to Play - Battle City Mokdong

The Mokdong branch of Battle City is unsurprisingly located near Mokdong station on the purple line (line 5).

Contact Details
Phone number: 02-2692-6279
Korean Street address: 서울특별시 양천구 신정동 902-3번지 목마빌딩 지하

* I have not been to this store and this info comes from online sources only.

Places to Play - Battle City, Geumjeong

Geumjeong is on line 1 (the dark blue line) and also intersects with line 4 (light blue line). I guess that makes it regular blue?

Take exit 5 is the information I have. 

They looked to have changed address recently which made people think they had closed.

Contact Details
Phone number: 02-939-6625
Email address: ohsooik@hanmail.net
Street address: 238-1, Sanbon-dong, Gunpo-si Gyeonggi-Do

238-1번지 3층경기도 군포시 산본동


* I have not been to this store and this info comes from online sources only.

Places to Play - Duel Zone, Nowon

They have a large online store and seem to be a franchise.
http://www.duelzone.co.kr/

Nowon station is near the end (or start depending on your perspective) of the light blue line (line 4) and intersects with line 7.

Contact Details
Phone number: 02-939-6625
Email address: ohsooik@hanmail.net
Korean Street address: 서울특별시 노원구 상계동 581-102 2층

* I have not been to this store and this info comes from online sources only.

Places to Play - Duel Shop Maebong

This store is very new and I am not even sure of the name yet. It's located neat Maebong station on line 3 a couple of stops from Nambu Bus Terminal.

Contact Details
Phone number: 02 574 6086

* I have not been to this store and this info comes from online sources only.